How long to prepare for SFAS rucking?

I know the obvious answer is as soon as possible, but if I jogged at 5 mph for an hour each day with a 45 lb weighted vest, how long until I would be reasonably prepared for the rigors of SFAS? ( this is of course in conjunction with a lifting/speed running plan )

I find jogging at such a slow pace is too brutal to maintain. A strategy I use is walk at 3.5 mph and run at close to 8 mph and alternate every telephone pole or whatever measurement you have close to that. Once you get in shape you can up your resting speed to 4-5mph but 5 mph for me is the speed where walking is almost worse than running. Realistically I'd want at least 6 months of rucking twice a week to be good to go. Injuries are really risky with rucking so having a good base is always going to help. For a bare minimum, if you're already a PT stud, you could probably get by with 3-4 months though.

How would you suggest manipulating the weight I'm carrying? As in, when to progress? For an idea of what im at, currently no weight I can run 5 miles in 32:30 and I can squat 245. My only practice with weight has been walking at 3.8mph and 3.0 incline on a treadmill holding 15 lb dbells for maybe 30 minutes at a time but that didn't drain me.

I'm going to go out on a limb here and guess you're not exactly a little guy. I'd focus on your run time because you're going to want to be at least sub-7 minute miles on a 5 miler. For rucking, just feel it out. Your brain will tell you when the weight is too much just like when you load up extra for a squat or your legs are still worn out. But screw all that treadmill dumbell stuff, that's not really as useful IMO. Park 3 miles from the gym and run/ruck and do your workout, and come back. Starting out, your numbers will drop and you'll have to walk back (or limp) but it'll definitely give you a great mental workout on top of it. Also I'd stop squatting. If you're trying to run 4-5 times a day and rucking once or twice a week, I find squatting does more damage then I'm comfortable with. If you miss those brutal leg days, find a hill and ruck up it for a few repeats or ruck up the stairs of your closest tall building. For your rucks though, use a pack. It's a whole different dynamic than a vest. You could probably start out straight at whatever the SFAS weight is (it's like 55lbs right?) and hit a 5k. If you really want, you can pop your cherry with a 2 miler, but considering you're not a complete neckbeard, I see no real reason why you can't start off with a 3-5 miler.

Thanks for the response! To hit a few points: the weight treadmill thing was because the trainer at my gym I'm friends with does it quite frequently with clients and I like to join in and be social, I'm around a 6:30 paced 5 miler already, were you suggesting that with a ruck?!? And size is 6 ft ish (barely over) and around 180 lbs. Also, I'm 17 y/o so I have a few years before I'm even eligible to try out so I'd like to build some muscle still with the squats before I really go with running and rucking training (but that doesn't mean I'm not going to start it anyway).

How does my size stack up to average SFAS candidate if you're familiar with it? And I walk 3 miles to get to the gym everyday, no car yet so that's covered.

Oh wow, yea I'm an idiot. Math is hard. For some reason I had 4 miles in my head. And since you have time, that's good with the squatting, but really you're at the weight limit already in terms of practicality. You're heaviest guy in kit will still probably be a bit under that but I'd start practicing fireman carries. It offers the practicality of a useful workout and it'll still destroy your legs like squatting does. Honestly you're like perfect size and I hate you for it.

I'm various forums, stew smith articles, and training guides. I have read do not run with excess weight, bad for the joints to add that much stress with no adjustment period. Just practice rucking. The only way to get better at something is to do it. Get a ruck sack, and get the fuck outside. But yeah. Most programs go from 12-26 weeks. So somewhere In there

In 2005 there was 2 x 5ish mile rucks the first week, land nav the second week (not really a "ruck run" but need to be comfortable), then team week the 3rd week with ruck plus other stuff twice a day for 4 days, then the long ruck on day 4 into day 5.

Basically, being comfortable with the ruck and at least 60lbs is a must. You will be so scared of weighing low that you will put rocks into your ruck to make sure. Everyone does.

Tactical athletes must have physical ability, stamina and strength to function in any environment. Similar to athletes who participate in competitive sports, tactical athletes must be strong, fast, agile, but also have the endurance to perform repeatedly in any situation.